Fig. 5

Optical recording of BIT with a complex excitation spread pattern. a Optical signals of an event of BIT recorded at 2 h after the application of Bleb (10 μM). Optical action potentials simultaneously detected by three elements (a, b, and c) of the photodiode array are shown. Right Sketch of the preparation illustrating the location of the photodiode array on the preparation. Open triangle with Stim Position of the stimulation. b Maps of the excitation spread for the second optical action potentials. The timing of the appearance of the second action potential at the anomalous focus is regarded as time 0. Sequential maps during the BIT shown in a are represented. The positions of the wavefronts are displayed as isochrone curves at 50-ms intervals. Gray arrow lines Pathways of the excitation spread, bold line indicated by B in the right map functional blocked area over which the excitation cannot conduct. Other symbols are as defined in Figs. 1, 3, and 4